Conventionally, a refrigeration apparatus including a refrigerant circuit in which a refrigeration cycle is performed has been broadly applied to an air conditioning system, a hot-water supply system, etc.
Patent Document 1 discloses the refrigeration apparatus of this type. The refrigeration apparatus includes a refrigerant circuit which is a closed circuit filled with refrigerant. In the refrigerant circuit, a compressor, a condenser, an expansion valve, and an evaporator are connected together. When operating the compressor, refrigerant compressed in the compressor is condensed by releasing heat to air in the condenser. The pressure of the refrigerant condensed in the condenser is reduced by the expansion valve, and then such refrigerant is evaporated in the evaporator. The evaporated refrigerant is sucked into the compressor for recompression.
Refrigerant represented by Molecular Formula 1: C3HmFn (note that “m” and “n” are integers equal to or greater than 1 and equal to or less than 5, and a relationship represented by an expression m+n=6 is satisfied) and having a single double bond in a molecular structure is used for the refrigerant circuit of Patent Document 1. It has been known that such refrigerant does not contain chlorine and bromine atoms, and has a small influence on destruction of the ozone layer.